This invention relates to edge guards such as those which are applied to the trailing edges of swinging closures in automotive vehicles. These products are referred to in the automotive industry as edge guards or door edge guards.
Various types of edge guards are disclosed in many of applicant's issued U.S. patents as well as certain of his pending U.S. patent applications. By way of example, reference is made to the following issued patents of applicant relating to insulated metal edge guards.
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Insulated metal edge guards pioneered by applicant have been accepted by the automobile industry and recognized as providing a new and improved product over prior edge guards. While applicant's edge guards afford a number of different types of improvements, perhaps the most significant one is the generic feature of essentially eliminating the possibility of galvanic action (i.e. rusting) occuring between metal of the edge guard and the metal of the door or other object onto which the edge guard is installed. This helps the automobile manufacturers achieve their desired objectives of improving the quality, appearance and life of their products.
Now that new car purchasers are keeping their cars longer because of the very high cost of new cars, it is in the automobile manufacturers' interest to provide products which will maintain their appearance longer without unsightly rusting. Not only does this benefit the original owner, but subsequent owners as well because one person's old car may be another person's new one. Applicant's pioneering efforts with insulated door edge guards predate this current trend toward rust prevention.
It should be recognized that a car's door edges are exposed to potential damage at least twice each time the car is occupied and driven, once when the driver gets in and once when he gets out. Hence, door edge guards provide an important protective function, and this is true regardless of the climate conditions in which the car is used. Certainly salt environments are very severe, such as where salt is used to melt road ice and snow, or along the ocean shore lines. Other environments can also contribute toward the tendency to rusting. Even where coal and sand are used, these materials may have a high salt or acid content which promotes rusting.
In furtherance of enabling the automobile manufacturers to improve both their products and their productivity, applicant is continuing to develop new and useful improvements in edge guards, both in the products per se and in the methods of manufacturing same.
The present invention is directed to a further improvement in an edge guard which provides improved characteristics yet which can be economically fabricated in various configurations and yet can provide new and beneficial appearances and ease of installation.
The present invention enables an edge guard to be manufactured which will meet the rigid specifications of automobile companies and with improved productivity.
In prior insulated metal edge guards, it has been necessary to laminate or cast plastic onto metal coils, slit the insulated metal of the coils to desired widths and then roll-form the strips. Where different plastics are involved, not only from the standpoint of the types of plastic materials themselves, but also from the standpoint of colors of the plastics, the manufacturer of an edge guard must inventory a substantial stock of insulated metal in order to meet the demands of automobile companies. With the present invention this is no longer required and hence the invention provides an improved productivity to the ultimate benefit of the consumer. Yet the desired qualities, both decorative and protective, are obtained with an edge guard embodying principles of the invention.
According to one aspect of the invention, plastic material is extruded onto a strip of metal in the flat with the strip of metal having a width corresponding to that which is required to form the cross section of a single edge guard. The plastic material may be applied to the metal strip in a desired pattern covering either the entire width of one side of the strip, or less than the entire width of the strip. Its thickness need not be constant across the width of the strip. The laminate consisting of the extruded plastic on the metal strip is then subsequently processed into a desired cross sectional shape for the edge guard, a U-shaped cross section being representative.
With the plastic being applied to the full width of the strip, the material is formed into a U-shaped cross section to dispose the vinyl on the interior of the U. This provides full insulation when the edge guard is applied onto the edge of a metal object such as the trailing edge of a swinging closure in an automobile. If it is desired to outwardly turn one or both of the distal ends of the legs of the edge guard, a bead or beads may be formed, each of which possesses an exterior appearance consisting of the plastic material and not the metal. This may be deemed desirable to provide a decorative appearance function and/or improved retention force for retaining the edge guard on an edge.
The use of metal can render the edge guard self-retaining so that it may be deemed unnecessary to use separate adhesives applied to the interior of the U-shaped cross section for the purpose of bonding the edge guard onto the edge of the object onto which it is to be installed.
In another embodiment, the plastic material is extruded onto the metal strip so as to cover only a portion of one side of the metal strip leaving one or both longitudinally extending margins on the same side of the strip uncovered. The strip may be then formed into a U-shaped cross section to dispose the insulation on the interior of the U. Like the preceeding embodiment, this can provide a full insulation of the metal of the edge guard from the metal of the edge. This embodiment also provides for the creation of beads at the distal ends of the legs. By leaving one or both longitudinal margins uncovered by plastic, these margins may be turned outwardly to form metal beads so that the beads have an exterior appearance of metal while yet the edge guard provides insulation lining the interior of the U so as to protectively insulate the edge guard from the edge.
According to a still further aspect of the invention, the cross sectional shape of the plastic extruded onto the metal strip may be of non-uniform thickness, for example a tapered thickness. By tapering the thickness such that the edge guard has a narrowing taper toward the longitudinal edges of the metal strip, and then forming the insulated strip into a U-shaped cross section to dispose the insulation on the interior of the U, the insulation is in effect feathered at the distal ends of the legs. This is advantageous in that it can facilitate the installation and retention of an edge guard on an edge while at the same time providing the desired edge guard function with improved protection of the edge from external forces which may be applied through the edge guard.
According to a still further aspect of the invention the material may be first roll-formed into a desired U-shaped cross section and vinyl or plastic material co-extruded onto the U-shaped cross section. This provides for various cross sections which cannot be obtained by extruding material onto the metal strip in the flat. Depending upon the desired exterior appearance, the edge guard may be constructed so that only the metal of the edge guard appears from the exterior, or selectively plastic may appear when beads are formed at the ends of the legs with the plastic appearing on the exterior of the beads. The dimensions and sizes of the edge guard may also be selected in accordance with desired characteristics. By controlling the thickness of plastic extruded onto the metal, it is possible for the plastic to be able to compensate for variances in the thicknesses of the edges onto which the edge guards are to be installed. For example, in the case of automobile doors the thicknesses of doors may depend upon the particular plants at which doors are manufactured due to the possibility of different tooling and different manufacturing procedures being used. By designing the edge guard with a sufficient thickness of insulating material to compensate for differences in thickness of the doors, it is possible for a single edge guard cross section to be compatible with doors manufactured at different manufacturing plants. This improves the productivity of manufacturing operations and facilitates assembly and inventory procedures.
The foregoing features, advantages and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.